1. Field of the Invention
The present invention relates to an image signal processor and an image display device that generate a red output signal, a green output signal, a blue output signal and a fourth color output signal in accordance with a red input signal corresponding to a red light component, a green input signal corresponding to a green light component and a blue input signal corresponding to a blue light component.
2. Description of the Related Art
Conventionally, there has been widely known a three-panel projection type image display device provided with a red liquid crystal panel configured to modulate a red light component, a green liquid crystal panel configured to modulate a green light component and a blue liquid crystal panel configured to modulate a blue light component.
Moreover, for the purpose of improving luminance and of reducing power consumption of light source, there has been proposed a projection type image display device that utilizes a fourth color light component (such as a white light component) in addition to the red light component, the green light component and the blue light component (for example, refer to Japanese Patent Publication No. 2004-280108 (claim 1, paragraph [0020], FIG. 5 or the like)).
Specifically, in a projection type image display device, an improvement in luminance of image projected on a screen and a reduction in power consumption of light source are achieved by substituting the white light component for the luminance components of the red light component, the green light component and the blue light component.
In the case of the aforementioned projection type image display device, however, an appropriate expansion of the color reproduction range of image cannot be achieved although the luminance of image projected on a screen can be improved by adding the white light component.
With this regard, the present invention is made to resolve the aforementioned problem. An object of the present invention is to provide an image signal processor and an image display device that make it possible to achieve the appropriate expansion of the color reproduction range of image.